1. Field of the Invention
The present invention pertains to the art of cooking appliances and, more particularly, to a cooking appliance including a control unit for varying operational parameters of the appliance based, at least in part, upon the current rating of a supply circuit.
2. Discussion of the Prior Art
A typical modern cooking appliance will include multiple electric heat loads, such as electric heating elements, convection fans and, in some cases, a microwave heating system. As a result, most modern electric cooking appliances are designed to operate on a high current rating, such as a 30 amp supply circuit. However, as older cooking appliances did not include all the modern amenities consumers now demand, they were designed to operate on a low current rating, such as a 20 amp supply circuit. Consequently, many older households are not designed to take full advantage of the many features provided in modern cooking appliances.
By design, modern appliances are programmed to operate multiple electrical loads simultaneously. For example, during a bake process, the electric heating element and the convection fan are operated. During other cooking operations, multiple heating elements are operated and, if so equipped, the microwave system can be used to perform a portion of the cooking process. Certainly, when multiple electrical loads are operated on a low current rated circuit, the circuit will overload and a breaker will trip, thereby cutting the current flow to the appliance and interrupting the cooking process.
In recognition of this problem, the prior art contains several methods of operating a cooking appliance so as to not overload the supply circuit. In one example, electrical current is delivered to a plurality of electric burners in bursts, such that the overall current draw on the circuit remains within the limitation of a circuit breaker. In other examples, each of a plurality of electrical loads is given a set order of priority and, either through use of an interlock system, a current sensor or through control programming, current is delivered to the loads in the set order of priority. While effective at preventing circuit overloads, each of the above examples have certain inherent limitations. If, for example, the low current rated circuit is upgraded to a high current rated circuit, the appliance will continue to operate the loads in the set order or priority and could not adapt to the new available current supply.
Therefore, despite the existence of prior art cooking appliances which operate to limit current draw on a circuit, there still exists a need in the art for a cooking appliance that can operate on a low current rated circuit and have the flexibility to adapt to a high current rated circuit in the future. Moreover, there exists a need in the art for an appliance that includes a control unit having stored therein multiple algorithms for operating the appliance based on the actual current rating of a supply circuit.